High sensitivity detectors for radon in air and in water have been developed. We use electrostatic collection and a PIN photodiode for these detectors. Calibration systems have been also constructed to obtain collection factors. As a result of the calibration study, the absolute humidity dependence of the radon detector for air is clearly observed in the region less than about 1.6 g/m3. The cal...

BACKGROUND Online hearing tests conducted in home settings on a personal computer (PC) require prior calibration. Biological calibration consists of approximating the reference sound level via the hearing threshold of a person with normal hearing. OBJECTIVE The objective of this study was to identify the error of the proposed methods of biological calibration, their duration, and the subjecti...

When spectral variation caused by factors different from the parameter to be predicted (e.g. external variations in temperature) is present in calibration data, a common approach is to include this variation in the calibration model. For this purpose, the calibration sample spectra measured under standard conditions and the spectra of a smaller set measured under changed conditions are combined...

This paper attempts to provide an answer to the question: To what accuracy can insertion-loss measurements be made on low-loss, multi-mode fiber-optic cables, patch cords, and modules having a variety of terminations? To answer this question, and to provide insight regarding the factors that dominate the measurement accuracy, a thorough analysis of the measurement process is required. Relevant ...

This paper presents an improved iterative nonlinear calibration method in the gravitational field for both low-grade and high-grade triaxial accelerometers. This calibration method assumes the probability density function of a Gaussian distribution for the raw outputs of triaxial accelerometers. A nonlinear criterion function is derived as the maximum likelihood estimation for the calibration p...

One of the essential factors influencing the prediction accuracy of multivariate calibration models is the quality of the calibration data. A local regression strategy, together with a wavelength selection approach, is proposed to build the multivariate calibration models based on partial least squares regression. The local algorithm is applied to create a calibration set of spectra similar to ...

This article presents a method for calibration of inertial sensors (gyroscopes and accelerometers). In the proposed selfcalibration method, interacted extended Kalman filter and maximum likelihood estimator are applied for estimation of motion state parameters and calibration parameters (biases and scaling factors), respectively. The extended Kalman filter is employed to estimate nonlinear Gaus...

Sediment rating curve (SRC) is a conventional and a common regression model in estimating suspended sediment load (SSL) of flow discharge. However, in most cases the data log-transformation in SRC models causing a bias which underestimates SSL prediction. In this study, using the daily stream flow and suspended sediment load data from Shalman hydrometric station on Shalmanroud River, Guilan Pro...

Background: In order to deliver the precise dose to the target in radiotherapy, absorbed dose to water at the reference point should be assessed. When the calibration procedure is performed for a reference dosimeter in the 60Co beam of a Secondary Standard Dosimetry Laboratory (SSDL), the total uncertainty in absorbed dose to water (Dw) is estimated to be approximately 1.5%. This study attempts...